The present inventions relates generally to tomography systems and, more specifically, to a combined tomography system. Even more specifically, the present inventions are directed to a gantry for a combined tomography system and supports located within a gantry of a combined tomography system for supporting a patient table extending into the gantry.
X-ray computed tomography (CT) scanners have been used for over twenty-five years to create images of cross-sectional slices of subjects, such as human patients, and are particularly used as a medical diagnostic aid. An x-ray CT scanner can produce a 3-dimensional anatomic image of a patient""s body.
An annular gantry normally supports many of the components of an x-ray CT scanner and includes an outer ring secured to a stand and an inner ring mounted for rotation within the outer ring. During a scanning procedure, a patient table is positioned through the center of the gantry and the inner ring is rotated about the table. The components supported by the gantry can include an x-ray tube for providing the x-ray beam, one or more high voltage power supplies, balancing weights, a data acquisition module, and a bank of detectors diametrically opposed from the x-ray source. At least some of these components are secured in the inner ring for rotation therewith.
Positron emissions tomography (PET) scanning is a more recently developed procedure that uses positron emitting radioactive isotopes to show function or metabolism, rather than anatomy as in x-ray CT scanning techniques. A PET scanner is made up of special radiation detectors called scintillators which are arranged in a ring configuration within an annular gantry. Basically, each detector has an associated partner detector oppositely located on the ring. This setup allows for the sensing and measurement of positrons emitted by radioactive isotopes injected into a patient. The measurements are processed through nuclear counting equipment and computers to produce 3-dimensional images that allow quantitation of the physiochemical process in the patient""s body. PET scanners are used to diagnose and monitor cancer, in addition to diseases of the heart, brain and lungs.
Recently, the results of different types of scanning procedures, e.g., PET and x-ray CT scans (and MRI and x-ray procedures), have been combined, or superimposed, to take advantage of the particular benefits of each procedure. Accordingly, a patient is first scanned using a first procedure, then scanned using a second procedure, and the results of both scans are combined using specialized software and computing systems.
In order to obtain tomographic images of a patient with either scanner, it is necessary that the patient be located exactly at a predetermined position inside the opening of an annular scan gantry of the apparatus. For this reason, such scanners have been provided with a patient handling couch or table which is moveable vertically to be in line with an axis of the scan gantry, and moveable axially in and out of the scan gantry. Some existing systems includes a patient support couch or table that is movable between two or more separate scanning machines, such as an x-ray CT scanner and a PET scanner.
What is still desired, however, is a new and improved gantry that supports the components of at least two scanning machines, such as an x-ray CT scanner and a PET scanner. In this manner a patient can be successively scanned by two types of scanning machines by simply repositioning the patient in the same gantry.
Since a gantry of a combined tomography system may need to be longer than a typical gantry, and require that a patient table extend further into the gantry during the scanning procedures, what are also desired are new and improved supports located within the gantry of the combined tomography system for supporting the patient table extending into the gantry. The supports will prevent significant deformation (e.g., bending) of the extended patient table, such that a patient on the table can be located exactly at a predetermined position inside the opening of the gantry of the combined tomography system.
The present inventions accordingly generally provide a new and improved gantry that supports the components of at least two scanning machines, such as an x-ray CT scanner and a PET scanner, and new and improved supports located within the gantry of the combined tomography system for supporting a patient table extending into the gantry.
According to one aspect of the present inventions, the gantry includes an annular outer support, an annular drum concentrically positioned within the outer support rotatable about a rotation axis of the drum, and an annular disk extending radially inwardly from an inner circumferential surface of the drum. At least one of the disk and the drum include structural members for receiving and supporting tomography scanning components on opposing first and second sides of the disk. Among other features and benefits, the gantry can be used for a combined tomography scanner system, e.g., combining an x-ray CT scanner and a PET scanner in a single machine.
According to another aspect of the present inventions, a scanner system includes an annular gantry rotatable about a horizontal center of rotation. The system also includes a non-rotating sleeve coaxially positioned within the annular gantry and rollers secured to an inner surface of the sleeve for supporting a patient table pallet extending into the sleeve. Among other features and benefits, the rollers are particularly useful for supporting a patient table extending into a long gantry of a combined tomography system during scanning procedures, e.g., x-ray CT and PET scanning procedures.
The foregoing and other features and advantages of the present inventions will become more readily apparent from the following detailed description of the disclosure, as illustrated in the accompanying drawing.